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Traditionally, surface coal mines in the Western United States have been limited by economics to depths between 150 to 200 feet. Utah International Inc., however, is now planning to strip coal its San Juan Mine in Northwestern New Mexico to depths ranging up to 400 feet while uncovering 20 feet of steam coal. This method is cost-competitive with nearby shallower coal deposits and underground mining of the same property. How trucks and shovels can pre-strip for a dragline, along with results of the planning process, comparison with alternate systems, capital requirements, operating costs and comparisons with other coal sources are all detailed. Also discussed are the major problems anticipated, how they might be corrected, and potential improvements to the concept. Introduction The San Juan Deep Stripping Project will be situated at Utah International's San Jean Mine. The mine is in the Four Corners region, so-called because four states enjoy a common border point about 30 miles to the northwest.(see Figure 1). The area is a semi-arid plateau region with an average elevation of 5,200 feet, receiving an average of 6 inches of precipitation annually

Jan 1, 1981

By R Valenta, A Littleboy

Geological heterogeneity is one dimension of complexity in mining. Significant effort is put into developing an understanding of this complexity so it can be used in resource estimation, mine planning and economic modelling. However, over the decadal lifespan of a mining venture, many other dimensions add to the complexity of a mining operation. These include: technological evolution, market fluctuations; investor confidence; social norms; local expectations; and ecosystem functionality. As with geology, these factors are all heterogeneous, uncertain, time varying and represented through sparse and incomplete datasets. Recent work (Valenta et al) is beginning to show us how these risks correlate in different global settings. By analysing data relating to known, but as yet undeveloped copper deposits, this work (the complex ore body database) is demonstrating that it is the combination of issues (both price sensitive and non price-sensitive) that determine the viability of a deposit for extraction in the 21st century.CITATION: Littleboy, A, Plint, N and Valenta, R, 2018. Mining as a complex system: do we need a new model?, in Proceedings Complex Orebodies Conference 2018, pp 41–43 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Ash M

The world-class iron ore mines at Mt Whaleback, Torn Price and Paraburdoo located in the Hamersley Province of Western Australia must mine the Mt McRae Shale to obtain high grade ore from the Dales Gorge Member of the Brockman Iron Formation. The Mt McRae Shale contains a black pyritic shale lithology that reacts with ammonium nitrate-based explosives. This paper provides an overview of the problems associated with mining this reactive rock type as well as the development of a comprehensive procedure to safely and efficiently blast, excavate and dispose of this material. The strategy used to develop the procedure involved raising the awareness of relevant site personnel to the risks associated in mining the Black Pyritic Mt McRae Shale, obtaining the commitment of these personnel that a detailed procedure was required and that any procedure developed must be followed, otherwise the potential risks such as premature detonation were high. It was also necessary that an on-going training program be implemented so that all relevant new employees would be educated as to the reasons for adhering to the Black Pyritic Shale Procedure.

Jan 1, 1995

By M Kongas, K Saloheimo

Concentrating lower and more variable grade ore resources to meet acceptable concentrate quality criteria requires removal of significant amount of gangue minerals. Monitoring plant feed mineralogy and concentrate by on-stream analysis has significant economic benefits in concentrate quality and recovery optimisation. There is a need to develop a sensitive slurry on-line analyser for silica, aluminium, magnesium and other light elements.On-line XRF elemental analysis technology, which is a routine practice in base metal concentrators is not able to measure lighter elements than calcium from slurry. Too much of the X-ray fluorescence signal from lighter elements is absorbed by water. The limitations in the direct measurement of silica and other light elements have restricted its use in some applications. Some light element slurry analysers have been developed based on prompt gamma neutron activation (PGNAA) method but they have not performed up to the expectations. This paper describes a new on-line elemental slurry analyser and the results of on-line laboratory tests.CITATION:Kongas, M and Saloheimo, K, 2013. Online light element slurry analysis, in Proceedings MetPlant 2013 , pp 93-101 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By R Dimitrakopoulos

The development of mineral resources is based on a spatial model of the orebody that is only partly known from exploration drilling and associated geological interpretations. As a result, orebody models generated from the available information are uncertain and may require the use of stochastic conditional simulation techniques. Multiple-point methods have been developed for petroleum reservoir modelling, enabling reproduction of complex geological geometries. This paper considers a multiple-point approach to capture the uncertainty of the lithological model. The implementation of the method at the Yandi channel iron ore deposit in Western Australia and performance characteristics are discussed. The uncertain lithological model translates into considerable grade-tonnage uncertainty.

Jan 1, 2007

Australia has historically been a world leader in mining innovations. This trend is reflected in the international patent records, which show that in recent years there has been some recovery in the number of patent filings arising from Australian research. These innovations occur across a wide cross-section of mining technologies and derive from both public and private sector research. Australian mining innovations are largely dominated by new processes and equipment, principally in the areas of rock drilling and coring, strata stabilisation, cutting tools, blasting, mine design and oil field exploitation. They include improvements in drill bits, rock bolts and accessories and wellbore systems. Another area that has received significant research attention has been the in situ thermal processing of coal deposits. High profile examples of Australian mining innovations include the æSORDMinerÆ, a remote-controlled mining machine for use in mining collapsing wet environments, and CSIROÆs SMART*CUT rock cutting pick that dramatically increases the rate of cutting hard rock. This paper will provide an overview of recent innovations in Australian mining, as reflected in the international patent records, including the organisations and individuals active in the field, and the technological nature of specific innovations.

Jan 1, 2008

By Ngai WCT

Over 90 per cent of the explosives in Hong Kong are used in civil engineering works. The Hong Kong Government controls all explosives and delivers on a daily basis to each site which it has licensed. Such deliveries need to be arranged the day before actual delivery. With the vagaries of the traffic in Hong Kong, contractors do not necessarily know the time of arrival of explosives. Contractors in general would like to reduce their exposure to these potential delays and the high cost of explosives deliveries. The high population density and urbanisation means that rock blasting has to be carried out in close proximity to other property. In order to protect life, property and utilities, it is not only necessary to employ proper blasting techniques but also to adopt effective safety measures. The Route 3 Advance Earthworks project is located on the north-west corner of Tsing Yi Island, Hong Kong. It is one of the Airport Core Programme projects for the new Chek Lap Kok Airport. Secured by Leighton Contractors (Asia) Ltd in early-1992, the work commenced in May of the same year, with completion and handover to the Hong Kong Government in May 1995.

Jan 1, 1995

The "Line of Lade", a generic term by which the great Broken Hill orebodies are collectively known, lies in the County of Yancowinna, New South Wales (NSW) at the south eastern extrenity of the Barrier Ranges. As the township of Broken Hill grew to a city (incidentally it was officially named Willyama but by exerting an enterprising community independence which is still evident today it outplayed officialdom and retained its descriptive name), two major areas of population developed, Broken Hill and South Broken Hill. These two main civic divisions are respectively north west and south east of their dividing line, the surface expression of the orebody. See Fig. 1. The border between the States of NSW and South Australia (SA) is drawn along longitude 1410 East whilst the city of Broken hill's official longitude is 1410 28' 14" East which means it is only 50 km from this political boundary. A latitude of 310 57' 03" South contributes to the harsh climate of high summer temperatures which is not mollified by any significant increase in altitude for Broken Hill is only 300 m above sea level.

Jan 1, 1983

By Tack K

During its 28-year life the MHD ISP smelter has gone through two phases, each of about a dozen years. The first phase was a learning one; in the second phase the lessons were applied and throughput and production rose strongly. Early experience revealed the robustness and the flexibility of the Imperial Smelting Process. The experience was demonstrated by strong increases in the throughput of mixed lead-zinc concentrates and of secondary (oxide) zinc materials. Purchased material quantities rose from 175 000 tonnes/year to 200 000. The required capacity increase of the IS furnace to smelt the higher throughput was achieved by relatively minor modifications; for instance a change to the internal furnace profile gained an extra two square metres in cross sectional area. The furnace hearth area has remained practically unchanged over its entire history. The paper concludes that there is still more potential to be drawn from the process and MHD intends to sustain raw material input at a new level of 240 000 tonnes/year. However, this rate will have to be achieved under the imposition of more stringent environmental and product quality standards than ever before.

Jan 1, 1993

Seven papers included in Session 8 of the Third International Mine Water Congress under the heading "Achievements in Mine Water Management & Research" have been reviewed. Only one paper, a case study by Masters on biological treatment of inorganically polluted effluent, has any connection with research in the sense of seeking new, generally applicable knowledge which would advance the frontiers of mine water management. The remainder deal with various aspects of the management of mine water ranging from investigation of the geology of a specific aquifer system through operating dewatering systems to the management of specific effluent disposal problems.

Jan 1, 1988

On the face of it this is an easily answered question. Modern technology and life as we know it today would be impossible without industrial minerals and the responsible utilisation of mineral resources is essential for the economic wellbeing of the nation. The quarrying industry supplies a high percentage of the industrial minerals used in New Zealand and our role therefore, is to ensure a constant supply of high quality roading and concrete aggregates so that society and the community as a whole can develop. We must do this in a manner which causes the least possible disruption to members of the community, which efficiently utilises all the valuable resources, which causes as little pollution as possible and last but by no means least, creates realistic profit for the operator. It is only by achieving a reasonable profit that we are able to continue in business and therefore play our part in the development of the country. Unfortunately, quarries have a poor image and are not generally popular, as on the whole, they are noisy, dirty and dusty and attract large trucks which create traffic problems. Judging by the amount of restrictive legislation with which we have to comply today, not even government or the local authorities want quarries which presents the industry with some serious problems, some of which will be outlined in this paper.

Jan 1, 1978

The decrepitation technique is a rapid means of measuring abundances, temperatures and to some extent the fluid compositions, of fluid inclusions in transparent and opaque minerals. The method has been used to investigate the hydrothermal fluid systems associated with gold mineralisation in the Tennant Creek, Pine Creek and Halls Creek Goldfields. At the Enterprise Mine, Pine Creek, several different stages of quartz veining are distinguished and within these, gradational changes in fluid temperatures and compositions help to define the centre and nature of the thermal system responsible for the mineralisation. In the surrounding Pine Creek region and at Tennant Creek and Halls Creek, the results were applied on a regional scale to characterize outcrops and aid in the discrimination between potentially mineral- ized and barren outcrops. The decrepitation method involves the heating of a small (lgm) sample of crushed and sized grains up to as high as 800 degrees celsius. During the heating the fluid inclu- sions within the grains develop sufficient internal pressure to physically burst, the temperature of such bursting being dependent on the type of fluid and the prevailing tem- perature at the time the inclusion was originally trapped. The resulting tabulation of the number of inclusion bursts per 10 degree temperature interval is plotted as a histogram of decrepitations versus tempera- ture and called a decrepigram. The decrepi- grams frequently show several distinct peaks at different temperatures which are caused by different populations of inclusions in the sample. The areas of the peaks indicate the abundances of inclusions in each population while the shape and mean temperature of the peak provides a guide to the type of fluids involved. Of particular importance in this study is the presence of decrepitation peaks at fairly low temperatures (around 2000 C. These are characteristic of C02 rich fluids which build up internal pressure very quickly when heated. The Enterprise Gold Mine at Pine Creek comprises a number of overlapping quartz vein systems hosted by Burrell Creek Formation sediments. The geology of this mine has been described at this conference by Dann and Delaney, who have defined several distinct stages of quartz veining based on structural, mineralogical and physical features of the veins. For this decrepitation study, 19 quartz samples from the mine and environs, including some from each stage of veining were collected. These results suggest that there are 4 major vein types, within 3 of which additional small variations can be discerned which are due to gradational changes in the temperatures and fluid compositions in the mine area.

Jan 1, 1984

By W R. Adamson

"Optimisation of drill and blast design and engineering can deliver a significant positive impact on the profitability of any mining operation; however, true engineering of the blasting process is less common than might be thought. The paper that follows explores this gap and suggests a process control-based approach to the challenge.The concept of applying modifications to drill and blast designs in order to achieve efficiency improvements in downstream mining processes is far from new. However, the author suggests that the practical application has become less than rigorous in a number of different sectors of the mining industry in a wide range of countries.There is a common tendency for the design process to become simplified to the point where the objective is merely the communication of instructions to field implementers (drillers, explosive suppliers, blasters, etc). In effect ‘design’ often degrades to ‘cut and paste’ with consequences that vary from mild to critical, with respect to the profitability of the business.Engineering of the drill and blast process involves the design function, not on a one-off basis but rather as a component of a more complete cyclical process that includes a statement of objectives, a design based on a suggested hypothesis, field measurement of results, comparison with the target ‘set point’ and the application of control measures followed by new measurement, including interpretation of the results in financial terms.When applied in this fashion, engineering provides practitioners with the means to optimise the drill and blast impact on the full spectrum business result of the mining activity.These concepts are discussed with reference to a surface gold mining operation applying run-of-mine heap leach extraction. Engineering optimisation by adapting process control and measurement techniques is demonstrated to be a key component of the solution set applied to generate enhanced operations productivity and stakeholder value. It is shown that a combination of rigorous measurement, model calibration and hands-on quality assurance/quality control facilitates the creation of a road map to profitability, stressing the need to consider economic trade-offs between operational expense (investment) and measurement of enhanced value (return on investment).The process, however, does not cease at this point. Implementation of true design practices, incorporating innovation and discipline in implementation or execution can drive the process to deliver demonstrable, technically validated outcomes. Furthermore, these technical results can be related to financially quantifiable impacts. However, this accomplishment does not guarantee that these gains or savings will reach the bottom line of those mining, quarrying and construction companies that begin the process with such high hopes.CITATION:Adamson, W R, 2015. Application of engineering discipline and a full-process optimisation focus – productivity to profitability without profuse pruning, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 3–12 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 24, 2015

By W Angerer

This paper describes the design of the marine riser structures, including the design measures for sealing and protection from flooding, dewatering and connection to the main tunnels, for the Gold Coast desalination plant in Queensland. The risers connect the intake and discharge tunnels to the ocean. Construction commenced on both in April 2007. The paper describes the key design criteria for the risers, the construction constraints that influenced the design and the design of the main elements of the risers and the connections to the tunnels.

Jan 1, 2008

By C Woodfull, S Munroe

Geological uncertainty is reduced by improved understanding of the relationship between regional-scale geological basement features (structure, composition, depth) and known local structural risk (such as recognised structural hazards at the mine). Coal mining and exploration entities can be more efficient and effective in managing geological risk at a range of scales. A more efficient and effective performance in forward interpreting and managing geological risk will result in a more efficient and effective exploration and also incremental or even significant mining cost improvements. In order to improve the understanding of basement features, a new 4D regional structural/basin framework for the Sydney Basin and the eastern part of the Gunnedah Basin has been constructed to provide primarily coal exploration and mining with a more integrated geological framework for ongoing subregional to mine-scale geological risk based studies. The model has been developed from a range of available regional geophysical and geological datasets, of variable detail and reliability, which have been brought together to generate a more robust structural and tectonic model than could be generated with any one single dataset. An initial regional structural model for the Sydney Basin was constructed in 2003 and an update to the model was released in 2005 (SRK Consulting, 2003; 2005). The development and ongoing refinement of the model was undertaken with financial and data support from a number of coal mining industry, gas exploration and government organisations. Prior to, and following the development of the regional structural/basin model and associated Information Base, a number of more area-specific studies have been completed, using the æbasement upÆ assessment approach. The methodology for developing comprehensive structural models, from the basement up, is outlined. The approach can be applied at a country-wide, regional or lease area scale. Case examples of where this approach has been used as an effective and efficient method in improving geological certainty and as a predictive tool to help manage geological risk are also presented.

Jan 1, 2006

A formalised approach to risk management has been regulated in the United Kingdom (UK) since the Construction (Design and Management) Regulations 1994 (CDM) came into force in 1995. These regulations have recently been revised in 2007. In response to a series of significant claims around the world the UK insurance industry published a code of practice for risk management of tunnels in 2003, and that was followed by an international version in 2006. Probably one of the main contributions of this new approach is the recognition that health and safety risks can best be addressed early in the process, initially by the owner and then by the designers. One of the aims is to achieve elimination of risks by good design. The advantage of a risk-based approach to tunnel design is that all risks are considered explicitly, and any residual risks in the design are communicated clearly to the construction team. This paper looks at the implementation of this formalised approach to risk management with reference to the A3 Hindhead Project. The design has been undertaken in accordance with the requirements of the CDM regulations, and also in compliance with the Joint Code of Practice for Risk Management of Tunnel Works in the UK. An outline of the risk-based design process used is provided, including examples.

Jan 1, 2008

The major coalfields of Australia are almost unique in the occurrence in some areas of CO partly or almost completely replacing CH4,t1e normal seam gas from metamorphism of coal due to time and depth of burial. This CO2 situation has some benefits but mostly it introduces particular safety problems result- ing from the high density of CO2 relative to air, magnifying problems of gas dilution in ventilation, and the greater affinity which coal has for CO2 than for CH4 increasing proneness to gas-dynamic phenomena. The occurrence of most CO2 seam gas can be directly related to igneous intrusion and to its associated pneumatolytic injections. Whilst intrusions locally increase the rank of coal by their contact metamorphic effect, normal coal metamorphism due to time and depth of burial continues after intrusion and injection together with the ongoing metamorph- ic production of CH . This new CH slowly displaces any CO to leave some present-day intruded coals with seam gas with reduced CO2 or even without any significant CO2 associat- ions. The seam gas maps of the Bowen and Sydney Basins and more detailed maps of specific areas exemplify these situations. Mining progress, plus more searching studies of igneous-coal relationships provide improved understanding of the factors involved.

Jan 1, 1986

By M Brewster

Goldfields Abosso Goldfields Limited (AGL) is a Ghanaian registered company that owns and operates the Damang Gold Mine. Gold Fields Ghana Holdings Limited holds a 71.1 per cent interest in AGL. The Damang concession held by Gold Fields Ghana Holdings Limited covers a total area of 271 km2 located 40 km north of the town of Tarkwa in the south-western part of Ghana. Gold Fields as a company registered on the New York Stock Exchange is legally obliged to be SOX (Sarbanes-Oxley). Sarbanes-Oxley Section 404 (SOX404) is on management assessment of internal controls. The Mineral Resource Management (MRM) function of AGL manages three Prospecting Licenses and two mining licences. At least ten pits/prospects are scattered along the two limbs of the Damang Anticline and have two main types of mineralisation notably Paleoplacer and Hydrothermal. Thus SOX404 procedures are put in place to treat each mineralisation type in the best way for reliable resource outputs and estimates. Generating auditable resources for AGL is a prime but most important function of MRM. Thus important checks are built and designed to ensure that all relevant geological and geostatistical inputs conform to procedures outlined under SOX404 requirements. More importantly sign offs are designed to ensure that technical personnel involved in all aspects of resource and reserve generation are satisfied and can be held accountable.

Jan 1, 2007

At the beginning of this year it was my pleasure and responsibility to take over the Presidency of our Institute from Mr A. A. Parish who, as did his predecessors, filled the office with distinction. It is a great privilege to address you as President and it is an occasion for my wife and family, and I am most grateful for your inviting them to the buffet dinner. Our Secretary (Miss Jacka), who processes all Presidents, has told me that there are neither questions nor discussions on Presidential Addresses, and that being so, I felt free to select a controversial topic. The address I have prepared is not strictly true to label; because I intend to include also the effect on agricultural production in Australia if Britain joins the European Economic Community (i.e. the Common Market).Three points of view are1. the European, which is one of equanimity deriving from the initial brilliant success of their scheme,2. the British, which is one of anxiety not to miss the bus, coupled with a commendable wish not to inimically affect existing Commonwealth arrangements,and3. the Australian, which is one of alarm.In England all are drawing their own conclusions on the subject and views range from the extreme desirability, to the extreme undesirability, of the United Kingdom joining.No one in Britain wants Australia, or New Zealand, to...

Jan 1, 1962

By Swift D. G

For some time the Electricity Trust of South Australia (ETSA) has been investigating the application of new mining methods and equipment to minimise the cost impact of the steadily increasing depth of mining brought about by the 20¦ dip of the coal seams at the Leigh Creek Coalfield. Exhaustive examination of all suitable mining systems showed that highly mechanised systems involving belt conveyors displayed no eco- nomic or operational advantages over shovel and truck methods. However, the configuration of the Leigh Creek coalfield allows for two quite different approaches to mining by shovel and truck. The current strip mining method involves removing overburden from the highwall in 60 m to 200 m wide strips to progressively expose the coal down dip, and requires all waste to be hauled to the surface. The alternative ter- race haulback method involves opening a boxcut to full depth at one end of the coalfield, then mining the full section along strike and placing the spoil in the mined out area. On a strictly economic basis, the latter is clearly advantageous, but the former has significant less tangible advantages. In deciding between the two methods ETSA is faced with the need to examine the applicability of each method under a wide range of possible future demands on the coalfield, and to assess the importance of many intangible factors.

Jan 1, 1989